Process of generating a renewable biofuel from a hydrotreated stream of condensed oxygenates

ABSTRACT

A renewable fuel may be obtained from a bio-oil containing C 3 -C 5  oxygenates. In a first step, the bio-oil is subjected to a condensation reaction in which the oxygenates undergo a carbon-carbon bond forming reaction to produce a stream containing C 6 + oxygenates. In a second step, the stream is hydrotreated to produce C 6 + hydrocarbons.

SPECIFICATION

This application is a continuation-in-part application of U.S.application Ser. No. 13/681,145, filed on Nov. 19, 2012, hereinincorporated by reference in its entirety.

FIELD OF THE INVENTION

The invention relates to a process of generating a renewable biofuelfrom biomass converted liquids containing C₃ to C₅ oxygenates by firstsubjecting the C₃ to C₅ oxygenates to a carbon-carbon bond formingcondensation reaction and then hydrotreating the resulting C₆+oxygenates. The condensation and the hydrotreating of the oxygenates mayoccur in a single reactor.

BACKGROUND OF THE INVENTION

Renewable energy sources, such as biofuels, provide a substitute forfossil fuels and a means of reducing dependence on petroleum oil. Inlight of its low cost and wide availability, biomass is often used as afeedstock to produce pyrolysis oil (which is relatively soluble inwater) or bio-oil which, in turn, is used to produce biofuel.

Many different conversion processes have been developed for convertingbiomass to bio-oil or pyrolysis oil. Existing biomass conversionprocesses include, for example, combustion, gasification, slowpyrolysis, fast pyrolysis, liquefaction and enzymatic conversion.Pyrolysis oil is the resultant of thermal non-catalytic treatment ofbiomass. The thermocatalytic treatment of biomass renders liquidproducts that spontaneously separate into an aqueous phase and anorganic phase. Bio-oil consists of the organic phase. Pyrolysis oil andbio-oil may be processed into transportation fuels as well as intohydrocarbon chemicals and/or specialty chemicals.

While thermolysis processes and other conversion processes produce highyields of such oils, much of the pyrolysis oil and bio-oil produced isof low quality due to the presence of high levels of low molecularweight oxygenates having 5 or less carbon atoms (C₅−). Such low MWoxygenates can be in alcohols, aldehydes, ketones, carboxylic acids,glycols, esters, and the like. Those having an isolated carbonyl groupinclude aldehydes and ketones like methyl vinyl ketone and ethyl vinylketone.

Such oils thus require secondary upgrading in order to be utilized asdrop-in oxygen free transportation fuels due to the high amounts of suchoxygenates. A known method for converting oxygenates into hydrocarbonsis hydrotreating wherein the stream is contacted with hydrogen underpressure and at moderate temperatures, generally less than 750° F., overa fixed bed reactor.

Transportations fuels predominately contain hydrocarbons having six ormore carbon atoms (C₆+) (though small amounts of C₅ hydrocarbons arepresent in some gasolines). Thus, hydrocarbons derived by hydrotreatingC₅− oxygenates are of little value in transportation fuels.Additionally, hydrotreating C₅− oxygenates consumes valuable hydrogen inthe reactor. Thus, the efficiency of secondary upgrading of pyrolysisoil and bio-oil is compromised by the presence of the C₅− oxygenates.

Alternative processes have therefore been sought for enhancing theefficiency in hydrotreating of oils derived from biomass. Processes forenhancing the yield of hydrotreated pyrolysis oil and bio-oil fromstreams containing C₅− oxygenates, especially C₃ to C₅ oxygenates, havebeen sought.

SUMMARY OF THE INVENTION

The invention is drawn to a process for treating pyrolysis oil orbio-oil wherein carbonyl containing C₃ oxygenates, C₄ oxygenates and C₅oxygenates and mixtures of such oxygenates are subjected to acondensation reaction prior to subjecting the oil to hydrotreatment. Thecondensation reaction forms carbon-carbon bonds to produce C₆+oxygenates which are subsequently hydrotreated to C₆+ hydrocarbons.

In an embodiment, the invention is drawn to a process for treatingpyrolysis oil or bio-oil wherein carbonyl containing C₃ oxygenates, C₄oxygenates and C₅ oxygenates and mixtures of such oxygenates aresubjected to a condensation reaction. The condensation reaction formscarbon-carbon bonds to produce C₆+ oxygenates. The C₆+ hydrocarbons arethen hydrotreated to C₆+ hydrocarbons.

The yield of hydrotreated oil from the pyrolysis oil stream or bio-oilstream may be enhanced by subjecting the carbonyl containing C₃-C₅oxygenates in a pyrolysis oil or bio-oil stream to a carbon-carbon bondforming condensation reaction and then hydrotreating the resultingcondensate(s).

In an embodiment, a renewable biofuel may be produced from a pyrolysisoil or bio-oil feedstream by first subjecting the carbonyl containingC₃-C₅ oxygenates in the oil to a carbon-carbon bond forming condensationreaction. The resulting stream is then hydrotreated to produce ahydrotreated feedstream. Hydrotreatment may occur in a separate reactoras the condensation or in the same reactor as the condensation. Arenewable biofuel may be rendered from the hydrotreated feedstream. Forinstance, a renewable fuel may be prepared by combining the hydrotreatedstream with a liquid hydrocarbon obtained from a refinery stream.

In another embodiment, a renewable biofuel may be produced from ahydrotreated pyrolysis oil or bio-oil by first feeding the stream to acondensation reactor, such as a distillation column, and then subjectingthe C₃-C₅ oxygenates in the stream to a carbon-carbon bond formingcondensation reaction followed by hydrotreating the resultingcondensates. The hydrotreated condensates may then be subjected tofractionation to render a C₆+ naphtha fraction having a final boilingpoint below about 420° F.

In still another embodiment, a renewable biofuel may be produced frombiomass by first separating a predominately liquid phase containingC₃-C₅ oxygenates from a treated biomass, forming condensates through acarbon-carbon bond forming reaction from the higher MW oxygenatecondensates, and then hydrotreating the condensates. The condensationand hydrotreatment may occur in separate reactors or in a singlereactor.

In yet another embodiment, the hydrotreated condensates may be subjectedto fractionation to render separate hydrocarbon fractions containing (i)C₅, C₆, C₇ and C₈ hydrocarbons and (ii) C₉+ hydrocarbons.

In addition, transportation fuels may be prepared from the resultingseparated hydrocarbon fractions.

In another embodiment, the hydrotreated condensates are separated into anaphtha fraction containing predominately C₆, C₇, C₈, C₉, and C₁₀hydrocarbons and a hydrocarbon fraction containing C₁₁+ hydrocarbons.

The C₃-C₅ oxygenates may include carbonyl containing moieties includingcarboxylic acids, esters, ketones and/or aldehydes.

In an embodiment, the carbon-carbon bond forming condensation reactionconsists of a Diels-Alder reaction.

In another embodiment, the carbon-carbon forming condensation reactionconsists of an aldol condensation reaction.

In another embodiment, the carbon-carbon forming condensation reactionconsists of a Robinson annulation reaction.

In yet another embodiment, condensation of the oxygenates may occur inthe presence of a heterogeneous acid catalyst. Preferred heterogeneousacid catalysts may include natural or synthetic zeolites, sulfonatedresins (such as sulfonated polystyrene, sulfonated fluoropolymers,sulfonated fluorocopolymers), sulfated zirconia, chlorided alumina, andamorphous SiAl.

In still another embodiment, condensation of the oxygenates may occur inthe presence of a basic catalyst. Preferred basic catalysts are thoseselected from the group consisting of alkaline oxides, alkaline earthmetal oxides, Group IIB oxides and Groups IIIB oxides and mixturesthereof. Included within such basic catalysts are MgO, CaO, SrO, BaO,ZrO₂, TiO₂, CeO and mixtures thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more fully understand the drawings referred to in thedetailed description of the present invention, a brief description ofeach drawing is presented, in which:

FIG. 1 is a schematic diagram of a representative process defined hereinwherein a biomass derived stream is condensed prior to introduction intoa hydrotreater.

FIG. 2 is a schematic diagram of a representative process using theinventive steps defined herein wherein the condensation reaction andhydrotreatment occurs in separate reactors.

FIG. 3 is a schematic diagram of a representative process using theinventive steps defined herein wherein the condensation reaction andhydrotreatment occurs in a single reactor.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The yield of C₆+ hydrocarbons from pyrolysis oil or bio-oil may beincreased by the process defined herein. The process consists of twoprincipal steps. In the first step, low value carbonyl containing C₃,C₄, and C₅ oxygenates within the stream are converted to heavier (C₆+)oxygenates in a condensation reaction. In the second step of theprocess, the heavier oxygenates are hydrotreated to render the C₆+hydrocarbons. The condensation reaction of the C₃, C₄, and C₅ oxygenatesto heavier (C₆+) oxygenates and the hydrotreatment of the C₆+ oxygenatesto render C₆+ hydrocarbons may occur in separator reactors or within thesame reactor.

FIG. 1 is a flow diagram wherein bio-oil or pyrolysis oil containingC₃-C₅ oxygenates is introduced into a condensation reactor prior totreatment of the stream with hydrogen in a hydrotreater. FIG. 3 is aflow diagram showing conversion of the bio-oil or pyrolysis into C₆+hydrocarbons in a single reactor. (Shale oil produced by pyrolysis,hydrogenation or thermal dissolution shall be included within the term“pyrolysis oil” as used herein.) The amount of water in the streamintroduced into the conversion reactor is typically no greater than 40volume percent, more typically less than 10 volume percent.

Prior to the condensation reaction, the biomass may be subjected to apre-treatment operation. After condensation of at least some of theC₃-C₅ oxygenates, C₆+ oxygenates, the condensed bio-oil mixture issubjected to deoxygenation by the introduction of hydrogen. Typicallyfrom 90 to about 99.99% of the oxygen is removed from the oxygenatesfrom hydrotreatment.

When separator reactors are used for the condensation reaction and thehydrotreatment, the oxygen typically complexes with hydrogen in thehydrotreater to form water which is decanted from the predominatelyhydrocarbon hydrotreated oil in the back of the hydrotreater unit. Theoil stream exiting the hydrotreater is thereby enriched in C₆+hydrocarbons.

The condensation reaction product consisting of a C₆+ oxygenates isproduced by a carbon-carbon bond forming reaction between two or moreC₃-C₅ oxygenates. It is possible for any two molecules of carbonylcontaining C₃-C₅ oxygenates to react with each other. Thus, any such C₃oxygenate, for example, may react with one or more such oxygenatesselected from C₃ oxygenates, C₄ oxygenates or C₅ oxygenates; any such C₄oxygenate may react with one or more any such oxygenates selected fromC₃ oxygenates, C₄ oxygenates or C₅ oxygenates; and any such C₅ oxygenatemay react with one or more any such oxygenates selected from C₃oxygenates, C₄ oxygenates or C₅ oxygenates. In addition, any C₃oxygenate, C₄ oxygenate or C₅ oxygenate may react with one or moreoxygenates having carbon content in excess of C₅. For example, a C₃oxygenate may react with a C₇ oxygenate; a C₃ oxygenate may react with aC₄ oxygenate and a C₇ oxygenate; a C₃ oxygenate may react with another aC₃ oxygenate, a C₄ oxygenate and a C₇ oxygenate; etc.

The oxygenates may be converted to higher molecular weight oxygenates inany reactor which affects carbon carbon bond formation. Suitablereactors may include a fixed bed reactor, a continuous stirred tankreactor (CSTR), a distillation column, a catstill (catalyticdistillation unit) a stripper, as well as a heat exchanger.

The condensation products may be further processed by hydrotreating toprovide renewable transportation fuels.

In a preferred embodiment, the mixture exiting the condensation reactoris deoxygenated in a hydrotreater having a catalytic hydrotreating bed.

Alternatively, the single reactor wherein the condensation reaction andthe hydrotreatment both occur contains a catalytic hydrotreating bed aswell as the catalysts for condensation of the C₃-C₅ oxygenates.

The renewable fuel produced in accordance with the process describedherein may be blended with a petroleum-derived fuel to produce a blendedrenewable fuel. For example, the renewable fuel may be blended with apetroleum-derived gasoline in an amount of at least 0.01 to no more than50 weight percent, including from about 1 to 25 weight percent andfurther including from about 2 weight percent to 15 percent by weight,of the petroleum-derived gasoline to produce a blended,partially-renewable gasoline. In addition, the renewable fuel may beblended with a petroleum-diesel to produce a blended,partially-renewable diesel fuel in an amount of at least 0.01 to no morethan 50 weight percent, including from about 1 to 25 weight percent andfurther including from about 2 weight percent to 15 percent by weight,of the petroleum-derived diesel. Further, the renewable fuel may beblended with a petroleum-derived fuel oil in an amount of at least 0.01to no more than 50 weight percent, including from about 1 to 25 weightpercent and further including from about 2 weight percent to 15 percentby weight, of the petroleum-derived fuel oil.

The pyrolysis oil or bio-oil containing C₃-C₅ oxygenates may originatefrom the treatment of biomass in a biomass conversion reactor. Biomassmay be in the form of solid particles. The biomass particles can befibrous biomass materials comprising cellulose. Examples of suitablecellulose-containing materials include algae, paper waste, and/or cottonlinters. In one embodiment, the biomass particles can comprise alignocellulosic material. Examples of suitable lignocellulosic materialsinclude forestry waste such as wood chips, saw dust, pulping waste, andtree branches; agricultural waste such as corn stover, wheat straw, andbagasse; and/or energy crops such as eucalyptus, switch grass, andcoppice. The biomass may be in a solid or finely divided form or may bea liquid. Typically, the water soluble content of the biomass is nogreater than about 7 volume percent.

The biomass may be thermocatalytically treated to render bio-oil or maybe thermally treated (non-catalytically) to produce pyrolysis oil.Either the bio-oil or the pyrolysis oil may be subjected to any numberof conventional treatments prior to being introduced into the reactorwhere condensation occurs. For instance, the liquid phase of the bio-oilor pyrolysis oil may be separated from the solids in a solids separator.The oil may then be purified, partially purified or non-purified and maybe produced within the same plant or facility where the renewablebiofuel is prepared or may be produced in a remote location. Further,where two reactors are used, the stream subjected to the condensationreactor may have been produced within the same plant or facility inwhich the hydrotreater is located. In addition, the biomass may havebeen treated in the same plant or facility where the renewable biofuelis prepared or produced in a remote location.

Exemplary treatment stages are illustrated in FIG. 2 and any number ofpermutations may be used in the process described herein. For example,biomass particles may be prepared from biomass sources and largerparticles by techniques such as milling, grinding, pulverization, andthe like. The biomass may also be dried by methods known to thoseskilled in the art.

Referring, for example, to FIG. 2, biomass may be introduced via line 10into a biomass conversion unit and be subjected to thermal pyrolysis,catalytic gasification, thermocatalytic conversion, hydrothermalpyrolysis, or another biomass conversion process. Biomass conversionunit may include, for example, a fluidized bed reactor, a cyclonereactor, an ablative reactor, or a riser reactor. In a biomassconversion unit, solid biomass particles may be agitated, for example,to reduce the size of particles. Agitation may be facilitated by a gasincluding one or more of air, steam, flue gas, carbon dioxide, carbonmonoxide, hydrogen, and hydrocarbons such as methane. The agitatorfurther be a mill (e.g., ball or hammer mill) or kneader or mixer.

FIG. 2 further shows that effluent from the biomass conversion unit maybe introduced into a solids separator via line 15. Suitable separatorsmay include any conventional device capable of separating solids fromgas and vapors such as, for example, a cyclone separator or a gasfilter.

In addition to the removal of heavy materials and solids, water may beremoved during the separation at 27. For instance, during an aldolreaction, water may be removed during separation. There must a densitydifference between the water and oil in order for the water and oil toseparate in the separator.

Solid particles recovered in solids separator may further be introducedinto a regenerator via line 20 for regeneration, typically bycombustion. After regeneration, at least a portion of the hotregenerated solids may be introduced directly into biomass conversionreactor via line 25. Alternatively or additionally, the hot regeneratedsolids via line 30 may be combined with biomass prior to introduction ofbiomass into biomass conversion reactor or may be purged from theregenerator via line 28.

Bio-oil or pyrolysis oil, having the solids removed is then introducedinto the condensation reactor via line 35. The bio-oil or pyrolysis oilstream typically has an oxygen content in the range of 10 to 50 weightpercent and a high percentage of C₃-C₅ oxygenates. Typically, from about1 to about 25 weight percent of the bio-oil contains C₃-C₅ oxygenates.Such oxygenates may contain carboxylic acids, carboxylic acid ester,ketones (such as methyl vinyl ketone and ethyl vinyl ketone) as well asaldehydes.

The mixture exiting the condensation reactor may then be introduced intothe hydrotreating unit via line 40 where the mixture is subjected todeoxygenation by the introduction of hydrogen. Hydrocarbons, water, andother by-products, such as hydrogen sulfide, are formed in thehydrotreatment operation. Prior to introduction into the hydrotreaterthe mixture exiting the condensation reactor having been enriched in C₆+oxygenates may be subjected to conventional treatments.

Subsequent to producing hydrocarbons in the hydrotreater, thehydrotreated stream may be subjected to any number of conventionalpost-hydrotreated treatments.

For instance, as illustrated in FIG. 2, all or a portion of thehydrocarbon stream may be introduced into a fractionator via line 45. Inthe fractionator, at least a portion of the material may be separatedthrough line 50 as light fraction, line 55 as an intermediate fraction,and line 60 as a heavy fraction. The light fraction may have a boilingrange below petroleum-derived gasoline and the intermediate fraction mayhave a boiling range comparable to petroleum-derived gasoline. The heavyfraction may have a boiling range comparable to diesel fuel. Forinstance, in an embodiment, the light fraction may have a boiling pointless between from about 150° F. to about 180° F., the intermediatefraction may have a boiling point between from about 180° F. to about420° F. and the heavy fraction may have a boiling point above 420° F.

FIG. 3 illustrates another embodiment wherein condensation of the C₃-C₅oxygenates to C₅+ oxygenates and hydrotreating of the C₅+ oxygenates toC₅+ hydrocarbons occurs in a single reactor. Referring to FIG. 3,biomass may be introduced via line 10 into a biomass conversion reactorand treated as set forth above. Effluent from the biomass conversionunit may then be introduced into a solids separator through line 15. Inaddition to the removal of heavy materials and solids, water may beremoved during separation and enter a second separator through line 65.In the second separator, one or more organic streams containing C₃-C₅oxygenates may still be separated from the water stream. One or more ofthese organic streams may then be introduced into the single reactorwherein condensation and hydrotreatment occurs.

All or a portion of the organic stream exiting the solids separator maybe fed into a fractionator through line 70. In the fractionator, atleast a portion of the stream may be separated as light fraction havingthe boiling point of naphtha. At least a portion of the naphtha streammay be fed into the single condensation/hydrotreatment reactor via line75. Further, a portion of the gaseous stream produced in the biomassconversion reactor may be compressed into a liquid stream. This liquidstream containing C₃-C₅ oxygenates may then be fed into the singlecondensation/hydrotreatment reactor.

The building of carbon-carbon bonds in the condensation reactor to formC₅+ hydrocarbons may progress via an enol or enolate addition to acarbonyl compound. Suitable reactions may include an aldol condensationor Michael addition reaction or a mixture thereof. In addition, thebuilding of carbon-carbon bonds in the condensation reactor may proceedby a cycloaddition reaction wherein two or more independent pi-electronsystems form a ring. Suitable cycloaddition reactions may include aDiels Alder reaction, a Robinson annulation reaction as well as mixturesthereof. These reactions can proceed via a base catalyzed anionicreaction mechanism or an acid catalyzed cationic reaction mechanism.

In a preferred embodiment, the cycloaddition reaction is a Diels Alderreaction wherein a conjugated diene or conjugated enone is reacted witha dienophile to render a cyclohexene or a dihydropyran or substitutedcyclohexene ring or substituted a dihydropyran. A low molecular weightcompound having an electron withdrawing group within the bio-oil orpyrolysis oil may function as the dienophile. Typically, the dienophileis a vinylic ketone or vinylic aldehyde represented by the C₃-C₅oxygenates of the bio-oil. A vinylic ketone or vinylic aldehyde can alsoserve as the conjugated enone. A representative reaction scheme of aDiels-Alder reaction followed by hydrotreating wherein lighthydrocarbons are converted to heavy hydrocarbons may be represented asfollows:

Further, the formation of C₅+ hydrocarbons may proceed by an aldolcondensation reaction. A representative aldol condensation reaction maybe represented by the following schematic pathway wherein an enol or anenolate ion reacts with an aldehyde or a ketone to form either aβ-hydroxyaldehyde or a β-hydroxyketone:

wherein R, R′, R″ and R′″ are each independently selected from the groupconsisting of hydrogen, hydroxy, C₁-C₈ alkyl, alkenyl, and cycloalkyl,C₁-C₁₀ mono- and bicyclic aromatic and heterocyclic moieties (includingheterocyclic groups derived from biomass), and carbonyls andcarbohydrates such as ethanedione, glyceraldehyde, dihydroxyacetone,aldotetroses, aldopentoses, aldohexoses, ketotetroses, ketopentoses,ketohexoses, etc., provided that both R″ and R′″ are not hydrogen. Thereaction can also proceed via an acid catalyzed cationic reactionmechanism.

The aldol condensation reaction may be a Claisen-Schmidt condensationreaction between a ketone and a carbonyl compound lacking an alphahydrogen wherein an enolate ion typically is added to the carbonyl groupof another, un-ionized reactant.

The reaction of carbonyl containing C₅− oxygenates in the condensationreactor may further proceed by a Michael addition wherein the carbonyloxygenate undergoes a 1,4 addition to an enol or enolate anion.

Further, the C₅+ hydrocarbons may be formed by a ring formation reactionsuch as a Robinson annulation reaction between a ketone containing aα-CH₂ group and a α,β-unsaturated carbonyl (like methyl vinyl ketone).In a Robinson annulation reaction, an enolate executes a Michaeladdition to the α,β-unsaturated carbonyl compound. This is followed byan intramolecular aldol reaction to form the keto alcohol by an aldolring closure followed by dehydration. Representative Robinsonannulations reactions include:

In both of these illustrated reactions, a deprotonated ketone acts as anucleophile in a Michael reaction on a vinyl ketone to produce a Michaeladduct prior to the aldol condensation reaction. The reaction can alsoproceed via an acid catalyzed cationic reaction mechanism.

Condensation of the C₃-0₅ oxygenates occurs in the presence of heat.Typically, the C₃-C₅ oxygenates are subjected to condensation by beingheated to a temperature from about 230° F. to about 450° F. The reactionmay be promoted and/or facilitated by the presence of a base catalyst oran acid catalyst.

In a preferred embodiment where two reactors are used, condensationoccurs by catalytic distillation wherein the catalyst is placed withinthe condensation reactor in areas where concentrations of reactants areelevated.

The use of base or acid catalysts may enhance the rates of non-concertedcarbon-carbon bond forming condensation reactions (such as an aldol orDiels Alder condensation).

Suitable base catalysts include alkaline oxides, alkaline earth metaloxides, Group IIB oxides and Groups IIIB oxides as well as mixturesthereof. Exemplary of such catalysts are MgO, CaO, SrO, BaO, ZrO₂, TiO₂,CeO and mixtures thereof.

Suitable acid catalysts are those homogeneous acid catalysts selectedfrom the group consisting of inorganic acids (such as sulfuric acid,phosphoric acid, hydrochloric acid and nitric acid); trifluoroaceticacid; organic sulfonic acids (such as p-toluene sulfonic acid,benzenesulfonic acid, methanesulfonic acid, trifluoromethanesulfonicacid, 1,1,2,2-tetrafluoroethanesulfonic acid,1,2,3,2,3,3-hexapropanesulfonic acid); perfluoroalkylsulfonic acids, andcombinations thereof. Often, the pKa of the organic acid is less than 4.Also suitable are metal sulfonates, metal sulfates, metaltrifluoroacetates, metal triflates, such as bismuth triflate, yttriumtriflate, ytterbium triflate, neodymium triflate, lanthanum triflate,scandium triflate, zirconium triflate, and zinc tetrafluoroborate.

In a preferred embodiment, a heterogenous acid catalyst is used such asa natural or synthetic zeolite, sulfonated resin (such as sulfonatedpolystyrene, sulfonated fluoropolymers, sulfonated fluorocopolymers),sulfated zirconia, chlorided alumina, or amorphous SiAl or a mixturethereof.

Exemplary zeolites include those of the ZSM-type, including ZSM-5 (asdisclosed in U.S. Pat. No. 4,490,566)) and zeolite beta (disclosed inU.S. Pat. No. 4,490,565).

Perfluorinated ion exchange polymers (PFIEP) containing pendant sulfonicacid, carboxylic acid, or sulfonic acid and carboxylic acid groups mayalso be used.

In a preferred embodiment, the acid catalyst is a fluorinated sulfonicacid polymers which may be partially or totally converted to the saltform. Such products include those polymers having a perfluorocarbonbackbone and a pendant group represented by the formula—OCF₂CF(CF₃)OCF₂CF₂SO₃ X, wherein X is H, an alkali metal or NH₄.Polymers of this type are disclosed in U.S. Pat. No. 3.282,875.

One particularly suitable fluorinated sulfonic acid polymer is Naflon®perfluorinated sulfonic acid polymers of E.I. du Pont de Nemours andCompany. Such polymers include those of a tetrafluoroethylene backbonehaving incorporated perfluorovinyl ether groups terminated withsulfonate groups. Exemplary of such copolymers are Nafion-H and Nafion®Super Acid Catalyst, a bead-form strongly acidic resin which is acopolymer of tetrafluoroethylene andperfluoro-3,6-dioxa-4-methyl-7-octene sulfonyl fluoride, converted toeither the proton (H+), or the metal salt form.

Further preferred are sulfonated polymers and copolymers, such assulfonated polymers of styrene and styrene/divinylbenzene, such asAmberlyst™ of Rohm and Haas, as well as sulfated silicas, aluminas,titania and/or zirconia; sulfuric acid-treated silica, sulfuricacid-treated silica-alumina, acid-treated titania, acid-treatedzirconia, heteropolyacids supported on zirconia, heteropolyacidssupported on titania, heteropolyacids supported on alumina,heteropolyacids supported on silica, and amorphous SiAl.

Mixtures of two or more acid catalysts may also be used.

When present, the acid catalyst is preferably used in an amount of fromabout 0.01% to about 10% by weight of the reactants.

The following examples are illustrative of some of the embodiments ofthe present invention. Other embodiments within the scope of the claimsherein will be apparent to one skilled in the art from consideration ofthe description set forth herein. It is intended that the specification,together with the examples, be considered exemplary only, with the scopeand spirit of the invention being indicated by the claims which follow.

EXAMPLES Example 1

A 316L stainless steel double-ended cylinder having a volume of 150 cm³and capable of withstanding working pressures up to 5000 psig (344 bar)was obtained from the Swagelok Company. The cylinder was filled with ⅔volume of bio-oil derived from the thermo-catalytic conversion ofbiomass. Air or nitrogen was introduced into the cylinder to fill theremaining volume. Both ends of the cylinder were plugged and thecylinder was placed into a programmable oven wherein the thermal cyclewas controlled by temperatures (room temp to 212° F.@5 deg/min, 213° F.to 450° F., 350° F. & 230° F.@5 deg/min, 1 hr@450° F., 350° F. and 230°F. After the cylinder was cooled to room temperature, it was opened atone end to relieve pressure build-up and the sample removed foranalysis. The cylinder was weighed before and after the application ofheat and no evidence of weight change was noted. Table 1 depicts thechanges in C₂-C₅ oxygenates and C₂-C₅ hydrocarbons between the startingbio-oil and the converted bio-oils:

TABLE 1 Species Start Oil N₂ - 230° F. N₂ - 350° F. N₂ - 450° F. wt %4.6 3.3 3.0 2.2 C₂-C₅ as Ox's wt % 3.1 2.2 2.0 1.4 C₂-C₅ as C'sTable 2 represents the gas chromatography/mass spectrometry analysis ofthe starting bio-oil and the heated samples:

TABLE 2 Start Oil N₂ - 230° F. N₂ - 350° F. N₂ - 450° F. OxygenatesFurans 1.91 1.80 1.48 1.57 Aldehydes 1.15 0.63 0.41 0.53 Ketones 3.352.62 2.50 1.51 Carboxylic 0.33 0.59 0.88 0.76 Acids Phenols 16.06 15.8015.48 14.97 Indenols 1.17 0.83 0.21 0.08 Diols 2.59 2.50 1.65 1.35Naphthols 0.43 0.28 0.21 0.24 Hydrocarbons BTEX 4.51 4.48 4.38 4.04Other 0.60 0.55 0.52 0.54 Polyaromatics Other Alkyl 1.32 1.32 1.16 1.20Benzenes Indenes 1.65 1.57 1.26 1.32 Indanes 0.17 0.19 0.18 0.18Naphthalenes 1.09 1.11 1.04 1.15

The majority of ketones, aldehydes and carboxylic acids in Table 2 wereC₃-C₅ oxygenates. Tables 1 and 2 illustrate the decrease in C₃-C₅oxygenates in the condensation reactor product after heat treatment. Incontrast, the other compound classes were essentially unaffected bytreatment in the condensation reactor.

Example 2

A double-ended cylinder described in Example 1 was filled with ⅔ volumeof a naphtha fuel stream. Nitrogen was introduced into the cylinder tofill the remaining volume. Both ends of the cylinder were plugged andthe cylinder was placed into a programmable oven wherein the thermalcycle was controlled from 213° F. to 450° F.@5 deg/min and then 1hr@450° F. After the cylinder was cooled to room temperature, it wasopened at one end to relieve pressure build-up and the sample removedfor analysis. The cylinder was weighed before and after the applicationof heat and no evidence of weight change was noted. The gc/ms data ofthe starting naphtha and the naphtha following completion of heating isset forth in Table 3. The majority of ketones, aldehydes and carboxylicacids in Table 3 were C₃-C₅ oxygenates. Table 3 illustrate the decreasein C₃-C₅ oxygenates in the condensation reactor after heat treatment.

TABLE 3 Start Naphtha Reacted Naphtha Oxygenates: Aldehydes 2.13 1.17Furans 1.51 1.30 Ketones 11.90 9.10 Carboxylic Acids 0.21 0.30 Phenols1.67 1.27 Hydrocarbons: BTEX 64.32 64.51 Other Benzenes/Toluenes 7.215.14 Indenes 1.05 0.74 Indanes 0.58 0.46 Naphthalenes 0.14 0.11

From the foregoing, it will be observed that numerous variations andmodifications may be effected without departing from the true spirit andscope of the novel concepts of the invention.

What is claimed is:
 1. A process for producing a renewable biofuel froma hydrotreated bio-oil which comprises: (a) subjecting a feedstreamcontaining carbonyl oxygenates to a carbon-carbon bond formingcondensation reaction, wherein the oxygenates are selected from thegroup consisting of C₃ oxygenates, C₄ oxygenates and C₅ oxygenates andmixtures thereof and further wherein the C₃, C₄ and C₅ oxygenatesoriginate from a bio-oil stream; (b) hydrotreating the condensates ofstep (a) to form a hydrotreated feedstream; and (c) generating a C₆+renewable biofuel from the hydrotreated feedstream wherein thecondensation in step (a) and the hydrotreating in step (b) occurs in thesame reactor.
 2. The process of claim 1, wherein the feedstreamcontaining carbonyl oxygenates is a naphtha feedstream.
 3. The processof claim 2, wherein the naphtha feedstream is a hydrocarbon distillateseparated in a fractionator.
 4. The process of claim 1, wherein thefeedstream containing carbonyl oxygenates originates from an aqueousstream removed from a solids separator.
 5. The process of claim 1,wherein condensation occurs in the presence of a heterogeneous acidcatalyst.
 6. The process of claim 5, wherein the heterogeneous acidcatalyst is selected from the group consisting of organic sulfonicacids; perfluoroalkylsulfonic acids; zeolites; sulfated transition metaloxides, and perfluorinated ion exchange polymers containing pendantsulfonic acid, carboxylic acid, or sulfonic acid groups; sulfonatedcopolymers of styrene and divinylbenzene; sulfated silicas, aluminas,titania and/or zirconia; and amorphous SiAl and mixtures thereof.
 7. Theprocess of claim 6, wherein the heterogeneous acid catalyst is selectedfrom the group consisting of ZSM-type zeolites, zeolite beta, sulfonatedfluoropolymers or copolymers, sulfated zirconia and amorphous SiAl. 8.The process of claim 5, wherein the heterogeneous catalyst is a zeolitebeta.
 9. The process of claim 1, wherein condensation occurs in thepresence of a basic catalyst selected from the group consisting ofalkaline oxides, alkaline earth metal oxides, Group IIB oxides andGroups IIIB oxides and mixtures thereof.
 10. The process of claim 9,wherein the basic catalyst is selected from the group consisting of MgO,CaO, SrO, BaO, ZrO₂, TiO₂, CeO and mixtures thereof.
 11. The process ofclaim 10, wherein the basic catalyst is a supported catalyst.
 12. Theprocess of claim 1, wherein the carbon-carbon bond forming condensationreaction is a Diels-Alder reaction.
 13. The process of claim 1, whereinthe condensates of step (a) are prepared through a Michael additionreaction.
 14. The process of claim 1, wherein the condensates of step(a) are prepared through a Robinson annulations reaction.
 15. Theprocess of claim 1, wherein the C₃ oxygenates, C₄ oxygenates and C₅oxygenates are selected from the group consisting of carboxylic acids,ketones and aldehydes.
 16. The process of claim 12, wherein the ketonesare methyl vinyl ketone and ethyl vinyl ketone.
 17. A process forproducing a renewable biofuel from biomass, the process comprising: (a)converting biomass in a biomass conversion reactor into gaseous, liquidand solid components; (b) separating solids from the liquid phase in asolids separator and separating the liquid phase into an aqueous phaseand bio-oil; (c) fractionating the bio-oil into two more distillates,wherein one of the distillates is naphtha; (d) feeding into a singlereactor a feedstream containing carbonyl-containing oxygenates andcondensing and hydrotreating the feedstream in the single reactor,wherein the oxygenates are selected from the group consisting of C₃oxygenates, C₄ oxygenates and C₅ oxygenates and mixtures thereof whereinthe feedstream fed into the single reactor originates from at least oneof the following streams: (i) the gaseous component from the biomassconversion reactor; (ii) the naphtha distillate; or (iii) the aqueousphase of step (b).
 18. The process of claim 17, wherein condensationoccurs in the presence of a heterogeneous acid catalyst.
 19. The processof claim 17, wherein condensation occurs in the presence of a basiccatalyst selected from the group consisting of alkaline oxides, alkalineearth metal oxides, Group IIB oxides and Groups IIIB oxides and mixturesthereof.
 20. The process of claim 19, wherein the basic catalyst isselected from the group consisting of MgO, CaO, SrO, BaO, ZrO₂, TiO₂,CeO and mixtures thereof.